Phase change and insulating properties container and method of use

ABSTRACT

A container and method for cooling beverages to an acceptable consumption temperature and then for maintaining that beverage temperature for a sufficient time so as to allow the beverage to be consumed is provided. The container includes a beverage chamber for receiving a beverage therein which is defined by an open top, a lid for reversibly sealing the open top, and a beverage chamber side wall. The beverage chamber side wall has an inner wall, an outer wall and a bottom portion. A reservoir side wall is disposed surroundingly at a spaced relationship to the beverage chamber side wall so as to define a reservoir therebetween. A phase change material is disposed in the reservoir.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to insulated containers and more particularly, the present invention relates to an improved container for cooling beverages to a temperature suitable for consumption and for maintaining the beverage temperature within an acceptable range for consumption which includes a beverage chamber for receiving a heated beverage and a phase change material reservoir surrounding the beverage chamber.

2. Description of the Prior Art

As is generally well-known, it is frequently desirable to maintain beverages at a temperature suitable for consumption over an extended period of time. However, the problem encountered is that when a hot beverage is left alone in a container it will continually cool down until the ambient temperature is reached. Therefore, there have been many attempts made in the prior art heretofore to create containers that alter the temperature of beverages before they are consumed. For example, in U.S. Pat. No. 6,170,100 to Kremesec et al. issued on Jan. 23, 2001, there is disclosed an insulated container for cooling hot beverages prior to consumption which includes an upper reservoir and a lower reservoir surrounding a beverage chamber. The upper and lower reservoirs communicate with one another through a passageway having a two-way valve. A fluid fills the upper reservoir in which it is allowed to absorb the heat from the beverage. Once the beverage has cooled to a consumable temperature, the fluid is transported back to the lower reservoir, and the container then behaves as a typical double-walled insulated container so as to maintain the temperature.

While this '100 patent recognizes the problems associated with cooling hot liquids before consumption, it is not without its shortcomings. A first shortcoming is that the patented container requires a mechanical valve to prevent the cooling fluid from moving between the two reservoirs at an inappropriate time. A second shortcoming is that the patented container device lacks an automatic mechanism to determine when it should switch from a state of cooling to a state of maintaining the temperature. Finally, this patented container suffers from the disadvantage in that it does not have a means for replacing the heat that is dissipated from the beverage into the surrounding environment.

Another device designed to alter the temperature of liquids in a container is found in U.S. Pat. No. 6,606,937 to Lassota issued on Aug. 19, 2003 which discloses a self-heating urn having warmer packs urn dispensing hot beverages and keeping them hot before they are dispensed. This Lassota patent recognizes the need to keep hot beverages hot, and it uses warmer packs to perform this function, where the warmer packs may contain phase change materials. However, it does not address the need to first cool a hot beverage and then maintain its temperature at an ideal temperature for consumption. There is no cooling function provided by this Lassota patent. Additionally, the warmer packs must be first activated by heating it with an external heating device. This is an extra step required to maintain the beverage temperature. Finally, this urn is utilized to transport the beverage from a place where it is prepared to a place where it is to be dispensed into another container. The beverage is not directly consumed from this patented urn.

Further, in U.S. Pat. No. 6,513,516 to Sabin et al. issued on Feb. 4, 2003 and U.S. Pat. No. 6,664,383 to Joseph et al. issued on Nov. 11, 2003, there are disclosed various flexible packaging devices for heating, cooling and dispensing products. The devices in both of these two patents rely on either exothermic or endothermic reactions or phase change material to either heat or cool their contents. However, both of these patents describe a device which is made of a flexible material to create a kind of pouch. The pouch is essentially used to prepare or cook the contents. These patented devices do not address the need to first cool a prepared hot beverage and then maintain an ideal temperature for consumption.

U.S. Pat. No. 6,722,153 to Jeuch issued on Apr. 20, 2004 discloses a self-cooling package for beverages which includes a cooling device internal to the package and a connection to a pumping device external to the package. As the pressure is reduced, the coolant evaporates and heat is extracted from the beverages. While this '153 patent uses a phase change material to extract heat from a beverage, it requires an external pump to effect the change. Furthermore, it does not address the need to keep the beverage at a specific consumption temperature range.

Accordingly, it would be desirable to provide an improved container for cooling beverages to a temperature suitable for consumption and for maintaining the beverage temperature within an acceptable range for consumption which is relatively simple and inexpensive in design, construction, and operation. It would also be expedient that the container includes a beverage chamber for receiving a heated beverage and a phase change material reservoir surrounding the beverage chamber.

The present invention represents an improvement over the above-discussed prior art patents. None of the prior art discussed above disclosed a container for cooling beverages like that of the present invention which includes a beverage chamber for receiving a heated beverage and a phase change material reservoir surrounding the beverage chamber.

SUMMARY OF THE INVENTION

Accordingly, it is a general object of the present invention to provide an improved container and method for cooling beverages to a temperature suitable for consumption and for maintaining the beverage temperature within an acceptable range for consumption which is relatively simple and inexpensive in design, construction and operation.

It is an object of the present invention to provide an improved container and method for cooling beverages to a temperature suitable for consumption and for maintaining the beverage temperature within an acceptable range for consumption on an efficient and cost effective basis.

It is another object of the present invention to provide an improved container and method for cooling beverages to a temperature suitable for consumption and for maintaining the beverage temperature within an acceptable range for consumption which a visual indication that that the beverage has reached an acceptable consumption temperature.

It is still another object of the present invention to provide an improved container for cooling beverages to a temperature suitable for consumption and for maintaining the beverage temperature within an acceptable range for consumption which includes a beverage chamber for receiving a heated beverage and a phase change material reservoir surrounding the beverage chamber.

In a preferred embodiment of the present invention, there is provided a container and method for cooling beverages to an acceptable consumption temperature and then for maintaining that beverage temperature for a sufficient time so as to allow the beverage to be consumed. The container includes a beverage chamber for receiving a beverage therein which is defined by an open top, a lid for reversibly sealing the open top, and a beverage chamber side wall. The beverage chamber side wall has an inner wall, an outer wall and a bottom portion. A reservoir side wall is disposed surroundingly at a spaced relationship to the beverage chamber side wall so as to define a reservoir therebetween. A phase change material is disposed in the reservoir.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and advantages of the present invention will become more fully apparent from the following detailed description when read in conjunction with the accompanying drawings with like reference numerals indicating corresponding parts throughout, wherein:

FIG. 1 is a side cut away view of a container for cooling beverages, constructed in accordance with the principles of the present invention and illustrated in an empty state with a lid disposed above;

FIG. 2 is a cross-sectional view of the container of FIG. 1, taken along the lines 2-2 thereof; and

FIG. 3 is a graph, illustrating the temperature lowering and maintaining efficiency of the present container as compared to a readily obtainable insulated mug.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

It is to be distinctly understood at the outset that the present invention shown in the drawings and described in detail in conjunction with the preferred embodiments is not intended to serve as a limitation upon the scope or teachings thereof, but is to be considered merely as an exemplification of the principles of the present invention.

It is also to be understood that while the description of the preferred embodiment is directed to the cooling and temperature maintenance of hot beverages, the present container can also be used to maintain the temperature of cold liquids. The present container, however, will not cool the liquids further but, instead, will through the same thermal properties as maintaining heat, keep the cold liquids cold for a longer period of time than if the present container is not used. Also, for clarity sake, the term “beverage” will be used throughout the description. The term “beverage” is meant to refer to any liquid, such as coffee, or partial liquid such as soup, that is placed into the beverage chamber of the instant container. Finally, while the drawings and descriptions reference the present container device as being cylindrical in shape, as that is the most common shape or beverage containers, those skilled in the art will quickly understand that the principles involved will also work with containers of other shapes and aspects ratios including shapes such as are commonly referred to as soup bowls. Finally while a nestled arrayed reservoir system is described, other configurations such as concentric and stacked reservoir systems are also contemplated by the inventor.

Referring now in detail to the drawings, there is illustrated in FIG. 1 a side, cut away view of a container 20 for cooling beverages to a suitable temperature for consumption and for maintaining the beverage temperature within an acceptable range for consumption, constructed in accordance with the principles of the present invention and illustrated in the empty state with a lid positioned thereabove. FIG. 2 is a cross-sectional view of the container 20 of FIG. 1, taken along the lines 2-2 thereof.

The container 20 of the present invention can be manufactured from any number of the standard materials and in the manners common known to those skilled in the art. Transparent translucent or opaque plastics or glass, stainless steel, ceramic, polystyrene foam, paper and cardboard are the preferred materials. Additionally, different materials may be used for different elements or components of the container 20. In order to more easily understand the construction and design of container 20, it is best to first think of it in sections: a beverage chamber 22, a phase change material reservoir 24, and an insulative reservoir 26. The beverage chamber 22 is further defined by an inner wall 28 and outer wall 30 which further define a beverage chamber wall 32, a bottom portion 34, an open top 36 and a lid 38. While the preferred embodiment illustrates an internally threaded open top 36 and an externally threaded lid 38, any other known means for reversibly sealing the beverage chamber is acceptable. For instance a friction seal may also be used. The open top 36 further includes overhang 40 which mates with the peripheral edge of the lid 38.

The phase change material reservoir 24 is further defined by an inner wall member 42 and outer wall member 44 which define phase change material reservoir side wall 46, beverage chamber outer wall 30, and a bottom member 48. The circumference of phase change material reservoir side wall 46 is greater than the circumference of beverage chamber wall 32. The phase change material reservoir side wall can also be viewed as a sleeve which fits down and over the smaller diameter beverage chamber. Phase change material reservoir 24 is therefore created by the space between the beverage chamber outer wall 30 and inner wall member 42. The circumference size difference between the beverage chamber wall 32 and the reservoir side wall 46 need only be sufficient to contain an adequate amount of phase change material and expansion of the phase change material. (as will described in detail below).

The insulative reservoir 26 is further defined by an inner wall member 50 and outer wall member 52 which define insulative reservoir side wall 54, phase change material reservoir outer wall 44, and a bottom member 56. The circumference of insulative reservoir side wall 54 is greater than the circumference of phase change material reservoir side wall 46. The insulative reservoir side wall can also be viewed as a sleeve which fits down and over the smaller diameter phase change material reservoir. The insulative reservoir 26 is therefore created by the space between phase change material reservoir outer wall 44 and inner wall member 50. The circumference size difference between the phase change material reservoir side wall 46 and the insulative reservoir side wall 54 need only be sufficient to contain an adequate amount of insulative material, air or vacuum to provide for reduced heat loss.

Alternatively, the insulative reservoir 26 may be completely eliminated, provided that the material from the reservoir side wall 46 is constructed has sufficient insulative properties for a particular application. Furthermore, in this case, the insulative reservoir side wall 54 may be combined with phase change material reservoir side wall 46 and made as a single wall and a single material.

The nestled array of the beverage chamber 22 and the reservoirs 24, 26 can best be seen in greater detail in FIG. 2 of the drawings. Insulative reservoir 26 is positioned in confluence with phase change reservoir bottom member 48 while phase change material reservoir 24 is positioned in confluence with beverage chamber bottom portion 34. In fact, either or both of the insulative reservoir bottom member 56 and the phase change material reservoir bottom member 48 may be molded as a single piece with beverage chamber bottom portion 34.

A phase change material 25 is placed in a sealed system created by the phase change material reservoir 24. The phase change material is any material that exhibits a change in phase at a desired temperature or within a small range of a desired temperature. A change in phase is generally exhibited by the changing from a solid state to a liquid state (melting) or from a liquid state to a gaseous state (boiling), or from a solid state to a gaseous state (sublimating). The reverse of these state changes is also considered a phase change. In particular, this includes the changing from a liquid to solid state (freezing), or from a gaseous state to either a liquid or a solid state (condensing).

Furthermore, many substances also exhibit phase changes within the solid, liquid or gaseous state. A material may for example remain a solid, but transition between two phases. Sometimes, this may be observable by a physical change in the material such as the material changing particle size, but this is not necessarily always the case. The best way to determine if a material exhibits a phase change at a desired temperature is to apply heat in a controlled manner within a calorimeter, and observe the heat flux. The initial temperature should be below the desired temperature. Sharp changes in the heat flux curve will indicate phase changes. The initial temperature should be below the desired temperature. As heat is applied to the material, the temperature will rise at a constant rate, until it reaches a phase change temperature. At the phase change temperature, the rate of temperature change will decrease noticeable or may even remain constant until all of the material has change to the new phase. After all of the material has changed phase, the temperature will again rise at a steady rate.

In addition to the phase change temperature, materials also are characterized by the amount of energy or heat that is absorbed or released when changing from one phase to another phase. For changes between liquid and solid states, this attribute is known as the heat of fusion. For changes between liquid and gaseous states, this attribute in known as the heat of vaporization. Such attribute can be expressed in terms of units of calories/mass.

Assuming that the phase change material chosen to be deposited in the phase change material reservoir 24 of the container 20 is selected because it exhibits a solid-to-liquid state change at the desired temperature, the heat of fusion can be used to calculate the optimal volume of the phase change material reservoir 24 that is required for a particular application. The particular application may need, for example, for a beverage which is prepared at 200 degrees Fahrenheit to be cooled to 135 degrees Fahrenheit and then to be maintained a temperature near 135 degrees.

Assuming that the beverage is substantially water based, the number of calories that is needed to be extracted from the beverage can be calculated by multiplying the size of the beverage chamber 22 times the specific heat of water. The ideal volume that is required for the phase change material reservoir 24 can then be calculated by dividing the number of calories to be extracted by the product of the heat of fusion and the density for the phase change material. Since the density of the phase change material may be different between the two phases, the minimum density should be used. Additionally, it may be desirable that the phase change material reservoir side wall 46 be fabricated from a material with elastic properties so that it can accommodate changes in the volume of the phase change material.

There are many commercially available materials that exhibit a phase change within a range that are particularly useful for cooling and maintaining the temperature of a hot beverage at a comfortable consumption temperature. Based on common experience, a comfortable consumption temperature is between 110 degrees Fahrenheit and 145 degrees Fahrenheit. In view of this, there are several formulations of paraffin waxes which are known to have melting temperature that fall within this range. The Candlewick Company of (city and state) manufactures and sells several formulations including their designated formulation CF with a melting point of 122 degrees Fahrenheit, formulation number 2530 with a melting point of 126 degrees Fahrenheit, formulation number 3035 with a melting point of 135 degrees Fahrenheit, and formulation number 4045 with a melting point of 142 degrees Fahrenheit. Additional formulations are possible by altering the oil content which has the effect of altering the melting point.

An additional feature of the container 20 is realized when the phase change material reservoir side wall 46, the insulative reservoir side wall 54, and an insulative material 58 disposed between the side walls 46, 54 are made from transparent or translucent materials, and the phase change material deposited in the phase change material reservoir 24 has a property that it changes color or opacity as it transitions between the two phases. The change in color or opacity can be used to indicate that the beverage has been cooled to a comfortable temperature for consumption. Furthermore, if the material that changes from an opaque or translucent state to a transparent state is used, then a design, message or other artwork may be printed on the phase change material reservoir outer wall member 44 such that the design message or artwork becomes viewable at the desired consumption temperature.

In use, the container 20 is allowed to reach equilibrium room temperature, which is defined to be about 50 degrees Fahrenheit to about 90 degrees Fahrenheit. A hot beverage, such as coffee, tea or soup, is then placed into the beverage chamber 22. The heat of the beverage is conducted to the sealed reservoir 24 containing the phase change material 25. The heat is absorbed by the phase change material as it changes phase. The beverage will be cooled as a result. The beverage will be cooled to approximately the temperature at which the material changes phase. Since the material is chosen to have a phase change temperature that is approximately equal to the comfortable consumption temperature of the beverage, the beverage is now ready to be consumed. Additional heat will be dissipated from the beverage into the environment. As this heat is dissipated, it will be replaced by the heat being released by the phase change material 25 as it changes back to its original phase. Once the material changes back completely to its original phase, the beverage will continue to be maintained at a comfortable consumption temperature by the insulative properties of the container 20.

FIG. 3 illustrates an example of the temperature lowering and maintaining properties of present container 20. As can be seen, a readily available insulated mug is depicted in a curve I. In the curve I. the mug is used with a lid and the starting temperature is approximately 173 degrees Fahrenheit. Over a period of an hour, the temperature drops only to approximately 135 degrees Fahrenheit. The superior functions of the present container 20 is depicted in a curve II. The same hot beverage at approximately 173 degrees Fahrenheit was placed into the beverage chamber 22 of instant container 20. Within 5 minutes, the temperature of the beverage drops to approximately 145 degrees Fahrenheit. After 10 minutes, the temperature drops to approximately 140 degrees Fahrenheit, but the rate of drop decreases and nearly matches the rate of decrease of the referenced mug depicted in the curve I.

The inventor believes that the primary reason for the effects of the present invention are due to the creation of the phase change material reservoir 24 in thermal communication with the beverage chamber 22, wherein the reservoir 24 is filled with the material 25 that exhibits a phase change within a small range of temperatures. In the case of the present container 20 that was constructed for use to create the data depicted in the curve II, the phase change material 25 used was paraffin with a phase change temperature around 140 degrees Fahrenheit. When the beverage is dispensed into the beverage chamber 22 the temperature of the phase change material 25 is quickly raised to its phase change temperature. This causes the material to change phase. The phase change causes heat to be extracted from the beverage which, in turn, is cooled. However, once the beverage reaches the temperature at which the material changes phase, no more heat is extracted, and in fact the heat is released back into the beverage as the material reverts back to its original phase. This heat that is released back into the beverage helps to maintain the temperature of the beverage as heat is lost from the beverage into the surrounding environment. The insulative nature of the insulative reservoir 26 also work to maintain the heat of the beverage after the beverage reaches the phase change temperature.

From the foregoing detailed description, it can thus be seen that the present invention provides an improved container for cooling beverages to a temperature suitable for consumption and for maintaining the beverage temperature within an acceptable range for consumption. The present container includes a beverage chamber for receiving a heated beverage and a phase change material reservoir surrounding the beverage chamber. The phase change material reservoir contains a phase change material which is chosen to have a phase transition temperature that is close to the comfortable consumption temperature for the beverage.

While there has been illustrated and described what is at present considered to be a preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made, and equivalents may be substituted for elements thereof without departing from the true scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the central scope thereof. Therefore, it is intended that this invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out the invention, but that the invention will include all embodiments falling within the scope of the appended claims. 

1. A container for cooling beverages to an acceptable consumption temperature and then for maintaining that beverage temperature for a sufficient time so as to allow the beverage to be consumed, said container comprising: a beverage chamber for receiving a beverage therein defined by an open top, a lid for reversibly sealing the open top, and a beverage chamber side wall, said beverage chamber side wall having an inner wall, an outer wall and a bottom portion; a reservoir side wall disposed surroundingly at a spaced relationship to said beverage chamber side wall so as to define a reservoir therebetween; and a phase change material being disposed in said reservoir.
 2. A container for cooling beverages as claimed in claim 1, wherein said open top is internally threaded and said lid is externally threaded.
 3. A container for cooling beverages as claimed in claim 1, wherein said open top is provided with an overhang which is sealed by said lid with friction.
 4. A container for cooling beverages as claimed in claim 1, wherein said phase change material is comprised of a paraffin wax.
 5. A container for cooling beverages as claimed in claim 1, further comprising a second reservoir side wall disposed surroundingly at a spaced apart relationship to said first reservoir side wall so as to define a second reservoir therebetween.
 6. A container for cooling beverages as claimed in claim 5, wherein an insulative material is disposed in said second reservoir.
 7. A container for cooling beverages as claimed in claim 5, wherein said second reservoir is filled with a gas.
 8. A container for cooling beverages as claimed in claim 5, wherein said second reservoir is evacuated so to form a vacuum.
 9. A container for cooling beverages as claimed in claim 1, wherein said phase change material changes from opaque to translucent within the acceptable consumption temperature range.
 10. A container for cooling beverages as claimed in claim 9, wherein an outer wall of said first reservoir side wall is printed with a design which is viewable when the beverage has reached the acceptable consumption temperature.
 11. A container for cooling beverages to an acceptable consumption temperature and then for maintaining that beverage temperature for a sufficient time so as to allow the beverage to be consumed, said container comprising: an outer sleeve having an inner wall member, an outer wall member, and a bottom member; a beverage chamber having a diameter smaller than said outer sleeve and being defined by a inner wall, an outer wall, and a bottom portion; said beverage chamber being inserted into said outer sleeve, said outer sleeve being attached to said beverage chamber at a spaced apart relationship so to define a reservoir therebetween; and a phase change material being disposed in said reservoir and having a phase change temperature at approximately the acceptable consumption temperature.
 12. A container for cooling beverages as claimed in claim 11, wherein said phase change material is comprised of a paraffin wax.
 13. A container for cooling beverages as claimed in claim 11, further comprising an insulative sleeve having a diameter larger than said outer sleeve, said outer sleeve being inserted into said insulative sleeve, said insulative sleeve being attached at a spaced apart relationship to said outer sleeve so as to define a second reservoir therebetween.
 14. A container for cooling beverages as claimed in claim 13, wherein an insulative material is disposed in said second reservoir.
 15. A container for cooling beverages as claimed in claim 13, wherein said second reservoir is filled with a gas.
 16. A container for cooling beverages as claimed in claim 13, wherein said second reservoir is evacuated so to form a vacuum.
 17. A method for cooling a hot beverage to an acceptable consumption temperature and then for maintaining the temperature within an acceptable consumption range which includes a container having a beverage chamber for receiving a beverage therein, a reservoir side wall disposed surroundingly at a spaced relationship to the beverage chamber so as to define a reservoir therebetween, and a phase change material being disposed in the reservoir for absorbing the heat from the beverage when it is above the acceptable consumption temperature and for returning the heat to the beverage when it is below the acceptable consumption temperature comprising the steps of: allowing the container to reach equilibrium room temperature which is below a phase change temperature of the phase change material; putting a hot beverage into the beverage chamber; cooling the hot beverage by transferring heat to the phase change material so that it changes to a new phase from its original phase at room temperature; waiting for the phase change material to change; and replacing heat to the hot beverage by transferring heat from the phase change material as it changes back to its original phase.
 18. A method for cooling a hot beverage as claimed in claim 17, wherein the change of phase of the phase change material is indicated by a change in color.
 19. A method for cooling a hot beverage as claimed in claim 17, wherein the change of phase of the phase change material is indicated by a change in opacity.
 20. A method for cooling a hot beverage as claimed in claim 17, further comprising the step of consuming the beverage directly from the container. 